The young migrant worker arrives at the forbidding coal mining town of Montsou in the bleak area of the far north of France to earn a living as a miner.

He embraces socialist principles, reading large amounts of working class movement literature and fraternizing with Souvarine, a Russian anarchist and political émigré who has also come to Montsou to seek a living in the pits, and Rasseneur, a pub owner.

Étienne's simplistic understanding of socialist politics and their rousing effect on him are very reminiscent of the rebel Silvère in the first novel in the cycle, La Fortune des Rougon (1871).

While this is going on, Étienne also falls for Maheu's daughter Catherine, also employed pushing carts in the mines, and he is drawn into the relationship between her and her brutish lover Chaval, a prototype for the character of Buteau in Zola's later novel La Terre (1887).

While the anarchist Souvarine preaches violent action, the miners and their families hold back, their poverty becoming ever more disastrous, until they are sparked into a ferocious riot, the violence of which is described in explicit terms by Zola, as well as providing some of the novelist's best and most evocative crowd scenes.

Accordingly, Zola ends the novel on a note of hope and one that has provided inspiration to socialist and reformist causes of all kinds throughout the years since its first publication: Beneath the blazing of the sun, in that morning of new growth, the countryside rang with song, as its belly swelled with a black and avenging army of men, germinating slowly in its furrows, growing upwards in readiness for harvests to come, until one day soon their ripening would burst open the earth itself.By the time of Zola's death, the novel had come to be recognized as his undisputed masterpiece.

Zola was always very proud of Germinal and was always keen to defend its accuracy against accusations of hyperbole and exaggeration (from the conservatives) or of slander against the working classes (from the socialists).

His research had been typically thorough, especially the parts involving lengthy observational visits to northern French mining towns in 1884, such as witnessing the after-effects of a crippling miners' strike first-hand at Anzin or actually going down a working coal pit at Denain.